Semiconductor photocatalysis has been considered as a potential technology for the removal of organic dyes from wastewater.The development of photocatalysts with high stability and strong catalytic activity is the mos...Semiconductor photocatalysis has been considered as a potential technology for the removal of organic dyes from wastewater.The development of photocatalysts with high stability and strong catalytic activity is the most important in application.Visible-light-induced NiCo_(2)O_(4)@Co_(3)O_(4) core/shell heterojunctions were synthesized via a sol-gel method in this paper.Compared to bare NiCo_(2)O_(4) and Co_(3)O_(4),NiCo_(2)O_(4)@Co_(3)O_(4) showed a remarkably enhanced removal rate towards congo red(CR)degradation with 98.4%of the removal rate to CR at 120 min under irradiation.The excellent performance of NiCo_(2)O_(4)@Co_(3)O_(4) benefits from the effective separation of photogenerated electron-holes by forming a heterojunction,and the rapid transfer efficiency of photo-generated charge carriers results from the core/shell architectures.A mechanism that NiCo_(2)O_(4)@Co_(3)O_(4) degrades CR to harmless inorganic substances by h^(+),•O-2 and•OH during the photocatalytic process was proposed.展开更多
A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called &q...A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called "Deep electro-oxidation" was used to generate manganese dioxide coated layer for stabilizing the electrode material. The structure and ingredient of the resulting MnHCF/MnO2 composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray Photoelectron Spectroscopy. Electrochemical testing showed a capacitance of 225.6 F/g at a sweep rate of 5 mV/s within a voltage range of 1.3 V, and high energy density of 37.2 Wh/kg at a current density of 0.5 A/g in galvanostatic charge/discharge cycling. It is suggested that the two different components, manganese hexacyanoferrate core and manganese dioxide shell, lead to an integrated electrochemical behavior, and an enhanced capacitor. The electrochemical testing and corresponding XPS analysis also demonstrated that the manganese coordinated by cyanide groups via nitrogen atoms in MnHCF did not get involved in the charge storage process during potential cycles.展开更多
As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such ...As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such as lower photoluminescence quantum yield(PLQY),complex synthetic pathways,uncontrollable emission spectra,and insufficient photostability.In this study,CuInZnS@ZnS core/shell QDs was prepared via a one-pot/three-step synthetic scheme with accurate and tunable control of PL spectra.Then their ensemble spectroscopic properties during nucleation formation,alloying,and ZnS shell growth processes were systematically investigated.PL peaks of these QDs can be precisely manipulated from 530 to 850 nm by controlling the stoichiometric ratio of Cu/In,Zn^(2+)doping and ZnS shell growth.In particular,CuInZnS@ZnS QDs possess a significantly long emission lifetime(up to 750 ns),high PLQY(up to 85%),and excellent crystallinity.Their spectroscopic evolution is well validated by Cu-deficient related intragap emission model.By controlling the stoichiometric ratio of Cu/In,two distinct Cu-deficient related emission pathways are established based on the differing oxidation states of Cu defects.Therefore,this work provides deeper insights for fabricating high luminescent ternary or quaternary-alloyed QDs.展开更多
AucoreCoshell nanoparticles with different shell thicknesses were prepared by using chemical reduction method and characterized by scanning electron microscopy（SEM） and cyclic voltammetry（CV）. The results reveal t...AucoreCoshell nanoparticles with different shell thicknesses were prepared by using chemical reduction method and characterized by scanning electron microscopy（SEM） and cyclic voltammetry（CV）. The results reveal that the prepared core-shell nanoparticles were covered by Co shell and exhibited the similar electrochemistry property with the Co nanoparticles surface. Surface enhanced Raman spectroscopy（SERS） activities of these nanoparticles were studied by using pyridine as a probe molecule. It was found that the SERS intensity depended on the Co shell thickness of the core-shell nanoparticles and was weakened with the increasing shell thickness. The SERS intensity of these AucoreCoshell nanoparticles is found to be about twenty times higher than that obtained on an electrochemically roughened cobalt electrode.展开更多
基金Project(2017TP1031)supported by the Hunan Key Laboratory for Rare Earth Functional Materials,ChinaProject(2020JJ4735)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(2018GK4001)supported by Science and Technology Department of Hunan Province Tackling Key Scientific and Technological Problems and Transformation of Major Scientific and Technological Achievements,ChinaProject(CSUZC202126)supported by the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University,China。
文摘Semiconductor photocatalysis has been considered as a potential technology for the removal of organic dyes from wastewater.The development of photocatalysts with high stability and strong catalytic activity is the most important in application.Visible-light-induced NiCo_(2)O_(4)@Co_(3)O_(4) core/shell heterojunctions were synthesized via a sol-gel method in this paper.Compared to bare NiCo_(2)O_(4) and Co_(3)O_(4),NiCo_(2)O_(4)@Co_(3)O_(4) showed a remarkably enhanced removal rate towards congo red(CR)degradation with 98.4%of the removal rate to CR at 120 min under irradiation.The excellent performance of NiCo_(2)O_(4)@Co_(3)O_(4) benefits from the effective separation of photogenerated electron-holes by forming a heterojunction,and the rapid transfer efficiency of photo-generated charge carriers results from the core/shell architectures.A mechanism that NiCo_(2)O_(4)@Co_(3)O_(4) degrades CR to harmless inorganic substances by h^(+),•O-2 and•OH during the photocatalytic process was proposed.
文摘A nanocomposite of manganese dioxide coated manganese hexacyanoferrate was synthesized by a facile co-precipitation method and tested as active electrode material for an electrochemical supercapacitor. A way called "Deep electro-oxidation" was used to generate manganese dioxide coated layer for stabilizing the electrode material. The structure and ingredient of the resulting MnHCF/MnO2 composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray Photoelectron Spectroscopy. Electrochemical testing showed a capacitance of 225.6 F/g at a sweep rate of 5 mV/s within a voltage range of 1.3 V, and high energy density of 37.2 Wh/kg at a current density of 0.5 A/g in galvanostatic charge/discharge cycling. It is suggested that the two different components, manganese hexacyanoferrate core and manganese dioxide shell, lead to an integrated electrochemical behavior, and an enhanced capacitor. The electrochemical testing and corresponding XPS analysis also demonstrated that the manganese coordinated by cyanide groups via nitrogen atoms in MnHCF did not get involved in the charge storage process during potential cycles.
基金Fund Project for Transformation of Scientific and Technological Achievements of Jiangsu Province of China(BA2023020)。
文摘As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such as lower photoluminescence quantum yield(PLQY),complex synthetic pathways,uncontrollable emission spectra,and insufficient photostability.In this study,CuInZnS@ZnS core/shell QDs was prepared via a one-pot/three-step synthetic scheme with accurate and tunable control of PL spectra.Then their ensemble spectroscopic properties during nucleation formation,alloying,and ZnS shell growth processes were systematically investigated.PL peaks of these QDs can be precisely manipulated from 530 to 850 nm by controlling the stoichiometric ratio of Cu/In,Zn^(2+)doping and ZnS shell growth.In particular,CuInZnS@ZnS QDs possess a significantly long emission lifetime(up to 750 ns),high PLQY(up to 85%),and excellent crystallinity.Their spectroscopic evolution is well validated by Cu-deficient related intragap emission model.By controlling the stoichiometric ratio of Cu/In,two distinct Cu-deficient related emission pathways are established based on the differing oxidation states of Cu defects.Therefore,this work provides deeper insights for fabricating high luminescent ternary or quaternary-alloyed QDs.
文摘AucoreCoshell nanoparticles with different shell thicknesses were prepared by using chemical reduction method and characterized by scanning electron microscopy（SEM） and cyclic voltammetry（CV）. The results reveal that the prepared core-shell nanoparticles were covered by Co shell and exhibited the similar electrochemistry property with the Co nanoparticles surface. Surface enhanced Raman spectroscopy（SERS） activities of these nanoparticles were studied by using pyridine as a probe molecule. It was found that the SERS intensity depended on the Co shell thickness of the core-shell nanoparticles and was weakened with the increasing shell thickness. The SERS intensity of these AucoreCoshell nanoparticles is found to be about twenty times higher than that obtained on an electrochemically roughened cobalt electrode.
